Continuous time weather regimes

 Weather regimes are computed for the four seasons (DJF, MAM, JJA and SON) on a reference period between 1970 and 2010. The whole SLP field is then classified on those reference weather regimes. Simple diagnostics are shown, with the occurrence of weather regimes in the current (or last) season, and the frequency of the weather regimes since 1948.

DJF Weather regimes

 MAM Weather regimes

JJA Weather regimes

SON weather regimes


The results are updated weekly. The files for the four seasons can be found at:

The pdf files show the weather regimes for each season (DJF, MAM, JJA, SON: see figure above for DJF). The dat files are the classifications of all days. The first column is the day (in yyyymmdd format). The second column is the weather regime number (identified in the corresponding figure). The third column is the distance to the weather regime.

You can use those files for your own research. They are updated every week. Please cite:

Yiou, P., Goubanova, K., Li, Z. X., and Nogaj, M.: Weather regime dependence of extreme value statistics for summer temperature and precipitation, Nonlin. Processes Geophys., 15, 365-378, doi:10.5194/npg-15-365-2008, 2008.


Legras, B. & Ghil, M. Persistent anomalies, blocking and variations in atmospheric predictability, J. Atmos. Sci., 1985, 42, 433-471

Vautard, R. Multiple weather regimes over the North Atlantic: Analysis of precursors and successors, Mon. Wea. Rev., 1990, 118, 2056-2081